If you are interested in Longstreet you will know it requires cards to play. There is an official set available from Sam Mustafa with the rules, which requires the action deck for one player, plus all the advanced cards for other features of the (advanced) rules and the campaign. However you do need to have 2 decks of the action cards for a standard game – the official deck will provide you one set for 1 player, plus all the advanced cards you need for both players. So to get a second action deck (assuming your regular opponent(s), or lack of the same, don’t have a set) you can either do as I have done and buy a second official set, or you can just use the lower quality free PDF from Sam’s Website to printout, stick to card, and cut out.
However I stumbled across this “Using Artscow For Longstreet Review” on the One Project Too Far blog – which discusses using an online printing service to create your own set of cards from the free PDF. This can be a cost effective way to get additional decks of the action cards if you are on a budget, without buying a second full official deck set.